Process of and oven for heat treating objects



Feb 23 1926. 1,573fi73 C.E.8EARCH PROCESS OF AND OVEN FOR HEAT TREATING OBJECTS Filed April 1'7, 1922 2 s w s 1 l 2 Feb. 23 1926. r 1,573,873 c. E. SEARCH PROCESS OF AND OVEN FOR HEAT TREATING OBJECTS Filed April 17, 1922 2 Sheets-Sheet 2 a place for pouring 'the s? Patented Feb. 23, 1926.

CHARLES EDW. SEARCH, OF MILWAUKEE, W'ISCONSIN.

PROCESS OF AND OVEN FOR HEAT TREATING OBJE CTS.

Application filed April 17, 1922.

To all whom it may concern Be it known that CHARLES EDWIN SEARCH, a citizen of the United States of Amenca, residing at Milwaukee, in the county of lllilwaukee and State of .Visconsin, has invented a certain new and useful Process of and Oven for Heat Treating Objects, of which the following is a specification.

This i vention relates to an oven and the process of using same in the fabrication or production of objects requiring heat to bring them to a state of perfection for use. The invention, as it has been developed, has been made in connection with what is known as a core even, an oven designed for the heating and drying out of cores as well as for the heating and drying out of formed molds. But the invention is not limited to core ovens, but is applicable to brick male ing, ceramics, etc, and while the description herein may be specific it is intended to apply generally. These core ovens have for their object the production of dry cores or molds so that the castings made from them are of better quality and not so liable to be chilled in places and thus more liable to breakage.

, The ordinary form of core oven is arranged horizontally with a door at one end opening into the core room, and it is provided with a car movable upon rails so as to transport the cores or molds loaded thereon from the core room or foundry into the oven to be heated. This usual arrangement is exceedingly wasteful of space, for it necessitates a place for making the cores or molds, a place for lOltCllilg same on the carriage, a place, an oven itsel for heating same llti the dried molds or t lose made up from the dried cores. This prior art therefore it will be observed, uses a four place floor space.

The present invention has for its object ting of valuable space as compared with prior practice. It contemplates the forming of molds or cores at one place, the loading of same onto a platform at a second place, the lowering of this platform into a pit oven, not requiring other floor space, and the transport of the heated cores or molds to a third place for use as by casting.

A. further object of this invention is the provision oi an oven so located in a floor pit, as to necessitate no considerable height above the floor at the pit for crane clearance.

A further object or the invention is the practicing of the art of preparing objects Serial No. 553,454.

by heating, in such a way that the workmen are always at the floor lever while doing their work on the said objects.

Further objects of the invention are out matters of detail and will be pointed the appended claims.

This invention will now he ll connection with the accompanying era forming a part of this specification which like characters e used in thc different views to represent the same or similar parts, and in which Fig. l is a transverse vertical sect ial view of the oven taken on the line l -l Pie. 2.

Fig. 2 is a plan view partly in section at the level of the burners.

Fig. 3 is a vertical sectional view, taken on the line XXL-III, Fig. 2, of the castings on top of the oven wall, and showing the cover plates.

Fig. l is a vertical sectional view of the same, taken on the line IV- IV, Fig. 2.

Fig. 5 is a schematic plan view of the upper flue castings lying on the oven wall and of the central bridge piece across the oven, showing the draft connection to a motor operated fan and to a chimney.

Fig. 6 is a fragmentary sectional plan view of a corner portion 01" the oven wall.

Fig. 7 is a fragmentary elevation of a corner of the elevator platform.

In the description of the invention, the term matrices will be used to rern'esent the more cumbersome terms cores or molds, and of course, as indicated above, bricks, ceramic ob ":4, etc, would be the equivalent.

'lhe floor level 1 is formed with a pit 2 lined with a wall 3 made of fire lirick. This wall 3 is reinforced by a structural steel frame l: and plate; 4.1 surroiuiding the same, the structural steel being comprised of two horizontal frame belt portions surrounding the oven at places more clearly indicated in Fig. l by the location of the two horizontal sets of square washers, (3. The frame 4.- further comprised of vertical sections of structural steel lying below, between and above the two horizontal surrounding belt portions, this sectional construction accommodating relative expansion between the wall 2-3 and its reeuiorcement without danger of shearing of the retaining bolts. This frame structure is held in place by bolts 5 and washers 6 on the inner face of the oven wall. The reinforcement is further comprised of metal guides 8 having a different ratio of expansion than the wall 3 and held in place by bolts 7 extending therefrom and through the wall 3 .and frame 4, with substantial clearance where they pass through the wall. These guides 3 may expand relatively to the wall 3 without damaging the bolts 7 by virtue of the clearance thus provided. A cylinder 9 extends downwardly into 'a recess at thebottom of the pit and is securely mounted therein. A pipe 10 supplies oil or water under pressure to the cylinder and exhausts the same therefron'i. A plunger 11 is mounted to reciprocate within the cylinder 9 and is properly packed by means of the gland 12 and packing 13 in the usual manner. A plat-form 1 1- is mounted upon the head-of the plunger and forms the bottom of the effective oven space. A rib 15 extends downwardly from the bot tom of the platform near its outer edge and coacts with a sand seal 16 provided at the bottom of the pit directly adjacent the oven walls. This platform 14C is preferably made in sections bolted together as clearly shown in Fig, 2 and is made strong by means of reinforcing ribs. The spaces between the ribs may be filled with sand and the top faced off with fire brick, with the object in view to prevent the heat from having access to the hydraulic parts below. The plat form 1 1 is provided with adjustable slides 17 fitting into notches at the corners of the platform at its top edge. These slides are fastened in place by cap screws 18 which fit loosely through holes 181 formed in the slides and these slides 17 are adjustable by means of cap screws 19 screwed through the side of the elevator platform as clearly shown in Fig. 7.

At the top of the oven are placed castings 20, 21,22, two of which, 20, 22, are U- shap'ed wall castings which abut at their ends the respective sides of the casting 21 which extend across the oven in the nature of a mid beam or runway. These castings 20, 21, 22 are hollow and form fines for taking off the gases from the oven. The arrangement of the fines is clearly shown in Fig. 5 where it will be seen that the two walls castings 20, 22 have upper outlets 26 for the gases, these being formed in two of the inner sides thereof, but of course they may be formed also on the third inner side.

The middle casting 21 has upper outlets 261 formed in its bottom, and it will be noted that the three castings 20, 21, 22 have their flue functions' entirely independent, leading off respectively by the pipes 33, 34, 35 to a pipe 36' which connects to fan 31 operated by a motor or by means of pipe 37 directly to chimney 38. The fan discharge 311 also connects to the chimney 38.

Lower outlets 27, 28 are alsoprovided in two opposite walls of the oven, and one of these, 27, connects with a vertical flue 29 extending up the wall and connecting at connections beingshown in Fig. 5 by means of pipe 30. Dampers 331, 341, 351 are provided for pipes 33, 3st, 35 leading from the fiues. Dampers 361, 371, 301 are respectively provided for pipes 36, 37,, 30, leading to the fansand chimney,

The upper outlets 26, 261,-conuecting with the hues of castings 20, 21, 22 may be selectively stopped off by means of metal covers 262 fastened in place in any convenient manner. One of these covers 262 is shown in place at the left of Fig. 3 but it is intended that other of these upper outlets 26 may be similarly closedotf as may be found neces sary or desirable under different conditions of operation.

Near the bottom of the oven space and just above the level of the platform in its lowermost position are provided burners 39 functioning through opposite walls of the furnace, three on a side, as clearly indicated in Figs. 1 and 2, These burners are indicated as ordinary oil burners but of course other heating means may be used such as coal or gas. It is preferable to have the heat developed directly within the oven, witlroil or gas burners.

Top castings 23 are preferably provided to lie above wall castings 20, 22 so as to insulate same at the floor level as may be seen from Fig. 4-. but of course a top casting may similarly be provided for casting 21. These top castings .43 are provided with a sand seal along their inner edges as is also casting 21 as shown. Cover plates 24 are provided, three edges of two of which lie in the sandseal of the top casting 23 and middle casting 21. The third cover plate 24;, three of these cover plates being shown at each,

side of middle casting 21, has two opposite edges in the sauc seal of top casting 23 and middle casting 21, and the remaining opposite edges thereof lie in matched recesses in the two cover plates already in place. any other arran ement, of course, can be provided that would suitably close off the top of the oven. 7

The operation and practice of this invention is as follows:

The elevator platform 1 1 is brought to its uppermost position adjacent the floor level and closely underneath the mid beam casting 21. In this position, formed matrices are placed thereonin a tier and as they are placed thereon, easily accessible to the workmen from all sides by reason of the mid beam casting 21 extending across the top of the pit, the necessary operations are conveniently performed such as blaclring, brush ing, slicking, etc. After this tier of matrices has been completed and dressed, the elevator is lowered to a position to bring this tier just below the floor level and a cond tier of matrices is loaded upon the platform, suitable plates being provided to rest upon the first tier of matrices, 0: suitable racks may be provided to support the second tier directly from the platforn'i by extending the racks down to the platform between the matrices of the first tier. This matter of support is an unimportant detail and may be accomplished in any desired manner, the essential point being that the matrices are loaded upon the elevator platform in tiers, so as always to have the dressing and loading atthe floor level. After the second tier is lowered and dressed a third tier may also be similarly placed thereon and dressed, and so on until the elevator is con'ipletely loaded when in its lowermost position. The cover plates are now placed over the oven, com pletely closing same. The burners 39 are now lighted and for a time the hot gas injected into theoven from the burners is drawn off through the lines leading from the upper outlets 26, 261. These flues deliver to pipes 33, 34;, and thence to pipe 36 delivering to the inlet of fan 31 the discharge 311 of which passes to chimney 38. After a time it may be found advisable to close ofi the fines leading from the outlets; this may be done by closing off dampers 331, S ll, 851. These may be separately or collectively closed off. If they are all closed off, it becomes desirable to have some other outlet for the gases, and in such case, damper 301 may be opened up so as to be able to discharge the hot gases from the lower outlets 28, through the pipe 30, see Fig. 5. This then provides for a discharge of the hot gases either from the top of the oven or from the bottom thereof. Another alternative provision for discharging the gases is by passing same through the fan or around the same to the chimney. The former may be accomplished by opening damper 361 of pipe 36 and closing damper 371 of pipe 37, the direct discharge'to the chimney being accomplished by a reversal of these damper positions.

After the matrices are thoroughly heated and dried, and this has been found to take about one-third the time ordinarily consumed with the horizontal type of furnace, the matrices are removed by a reverse series of stens to that of the loading; that is, the cover plates having been removed from the top of the oven, the elevator platform is raised so that the last tier of matrices placed thereon is at or adjacent the floor level. This tier being removed, the elevator platform is again raised to bring the next tier or adjacent the floor level and then this is removed, and soon.

It will be seen that in the practice of this invention both time and space are saved and the workman are at all times operating nca r the floor level.

It should he understood that it is not dc. sired to limit the invention to the exact steps of the process described or to the exact details of construction of the apparatus shown and described, for obvious n'ioditications will occur to persons skill d in the art.

It is claimed and desired to secure by Letters Patent:

1. An oven comprising a platform \(.E'tlcally adjustable to different levels and having its upper limit of adjustment adjacent the floor level, and a stationary beam ontending across said platform at the lloor level.

2. In combination, a pit oven, an elevator platform therein, a plunger for operating said platform, and a sand seal between said platform and pit itall.

In combination, a pit having its opening at the floor level and forming an oven chamber, an elevator platform in said pit, means for adjusting said platform to vari ous levels and adjacent the floor level as a limit, and means for permitting crossing of said pit at the floor level at all times.

4. The process of fabricating objects comprising loading a platform adjacent the floor level with a tier of formed objects, dressing said objects, lowering said platform into a pit until the top of said tier is adjacent the floor level, further loading said platform with a second tier of formed objects, dressing said second tier, lowering said platform farther into said pit to brii said second tier below the floor level, covering said pit, applying heat to said objects, uncovering said pit, elevating said platform to its second position, remoi-ing said second tier of objects, elevating said platform to its original position and removing said lire-t tier of objects.

5. The process of fabricating matrices comprising forming matrices at a selected place, transporting formed matrices to a second selected place, dressing said matrices at said second place at the floor level, lowering said matrir.:e.s immediately below said floor level, placing other said formed matrices immediately above said lowered matrices, dressing said other matrices, lowering all of said dr '1 matrices, confining same Within a chamber at said second place, drying name by heating within said chamber, elevating same, and removing same to a third selected place for use.

6. In an oven, means forming a chamber, a platform within said chamber, said means and said platform being relatively vertically movable, means for delivering heating medium into the bottom portion of said chamber, and means for effecting discharge said conduit means.

position, and means .medium into a of said medium from the upper side and central portions of said chamber.

7. In an oven, means forming a chamber, a platform within said chambe li said means and said platform being relatively vertically movable, means for delivering heating medium into the bottom of said chamber at opposite sides thereof, and means for effecting discharge of said medium from the bottom and top portions of said chamber, said bottom discharge means being located at the chamber sides other than these containing said delivery means.

8. In an oven, means forming a chamber, a platform vertically movable within said chamber, means for delivering heating medium into said chamber adjacent to said platform when the latter is in its lowermost for effecting discharge of said medium from upper side and central portions of said chamber.

9. In an oven, meansv forming a chamber,

a platform vertically movable within. srid chamber, means for deliver ng heating medium into sa l, chamber adjacent to said platform when the latter-1s n its lowermost position, means for effecting discharge of a part of said medium from a lower portion of said chamber, and means for effecting discharge of the remainder of said medium from an upper portion of said chamber.

10. In an oven, means forming a chamber, a platform vertically movable within said chamber, means for delivering heating bottom portion of said chamber, means for effecting discharge of said mediumfrom lower and upper portions of said chamber, and means for effecting closure of certain of said discharge effecting means.

11. In an oven, meansforming a chamber, platform vertically movable within said chamber, means for delivering heating medium into a lower portion of said chamber, conduit means spanning portion of said chamber, and means for effecting discl'iarge of said medium through 12. in an'oven, means forming a chamber, a platform vertically movable within saidchamber, means for delivering heating medium into a bottom portion of said chamber, means for effecting discharge of a portion of said medium from a lower portion of said chamber and at the sides thereof other than those at which said heating. medium is admitted, and means for effecting discharge of the remainder of said medium from upper side and central portions of said chamber.

13; In an oven, :1 wall of one material, a.

the upper guide of another material having a different ratio of expansion, bolts penetrating said wall and connecting said wall and guide, a platform movable within said oven and coacting with said guide, andmeans providing for relative expansion of said wall and guide without liability of shearing said bolts.

ll. in an oven comprising a vertically adjustable platform, the combination of a side wall, a metal structure reinforcing said wall, and a vertical guide for said platform sup ported by said structure. I

15. In an oven comprising a vertically adjustable platform, the combination of a side wall, a n'ietal structure reinforcing said wall, and a vertiial guide for said platform supported by said structure, and an adjustable slide on said platform coacting with said guide.

16. An oven comprising a floor pit and an elevator platform bottom, and a stationary beanli extending across the pit at the a001- leve 17. in oven comprising a floor pit and an elevator platform bottom, and a beam extending over the pit at the floor level, said beam being hollow and serving as a flue.

18. In an oven comprising a floor pit means for heating same by injected hot an exhaust flue adjacent the floor line and means for insulating said flue at said floor level.

v19. In combination with an. oven heated by entering hot gases, an exhaust outlet for said gases, a fan suction-connected to said outlet, a chimney connected to said outlet, and means for interchangeably withdrawing said gases by said fan and chimney.

20. In combination, an oven comprised of brick side walls, a plate coasting with the exterior of each of said walls, and reinforcing structure surrounding and uniting all of said plates.

21.111 an oven comprising a vertically adjustable platform, the combination of a side wall, metal structure reenforcing the outside of said wall, and a vertical guide for said platform supported by said structure on the inside of said side wall. v

22. In an oven comprising a vertically adjustable platfo m, the combination of a side we l, metal structure reenforcing the exterior of said wall, a vertical guide for said platform supported by said struc ture adjacent the interior of said side wall,"

and an adjustable slide on said, platform cooperable with said guide.

In testimony whereof the signature of the inventor is affixed hereto. C. EDN. SEARCH. 

